Punnett Squares

Front

What is a Punnett Square?

Back

A Punnett Square is a diagram used to predict the genetic makeup of offspring from two parents based on their genotypes.

Front

What does 'dominant' mean in genetics?

Back

A dominant trait is one that is expressed in the phenotype even if only one copy of the allele is present.

Front

What does 'recessive' mean in genetics?

Back

A recessive trait is one that is only expressed in the phenotype if two copies of the allele are present.

Front

What is the genotype of a homozygous dominant individual?

Back

The genotype of a homozygous dominant individual consists of two identical dominant alleles, represented as 'AA'.

Front

What is the genotype of a homozygous recessive individual?

Back

The genotype of a homozygous recessive individual consists of two identical recessive alleles, represented as 'aa'.

Front

What is a heterozygous genotype?

Back

A heterozygous genotype consists of one dominant and one recessive allele, represented as 'Aa'.

Front

How do you calculate the probability of a trait using a Punnett Square?

Back

To calculate the probability, fill in the Punnett Square with the parents' alleles and count the occurrences of each genotype.

Front

What is the probability of offspring having a dominant trait if one parent is homozygous dominant and the other is homozygous recessive?

Back

100% of the offspring will have the dominant trait.

Front

If two heterozygous parents (Aa) mate, what is the probability of having a homozygous recessive offspring?

Back

25% probability of having a homozygous recessive offspring (aa).

Front

What is the phenotype ratio of offspring from a cross between a homozygous dominant (AA) and a heterozygous (Aa) parent?

Back

100% will show the dominant phenotype.